Electrosurgical instruments are known, which impact biological tissue by generating sparks and which supply the light generated thereby to an analysis device.
For this purpose, WO 2011/055369 A2 discloses a micro plasma head for medical applications. This micro plasma head is formed by means of an elongated flexible instrument, at the end of which provision is made for electrodes for generating plasma. A light guide, the open front surface of which forms a light inlet window, ends so as to be slightly recessed. A plasma, the light of which is absorbed by the light inlet window, forms in front of the light inlet window. The connected light analysis device examines the light spectrum of the light emanating from the plasma in particular for the presence of a characteristic phosphor line. This serves for the differentiation of living tissue of plaques in response to the use of the instrument for removing plaques in blood vessels.
A more subtle light examination is proposed by U.S. 2007/0213704 A1. The elongated instrument illustrated therein encompasses an optical fiber in the center, which ends in a spherical recess of a ceramic end piece. Two sharp-edged electrodes, which generate a plasma in this recess, are also arranged in this recess.
A successful spectral light analysis requires for the light to reach to the spectral analyzer.